In order to record a video picture displayed on an image plane, a video camera or video recorder usually records a displayed video signal as such.
As disclosed in the published Japanese Patent Application No. 2002-94996, some pieces of recent data-transceiving equipment for displaying, and receiving multi-media data are designed to decode and then, blend several pieces of received encoded image data with each other, thereby displaying the resulting display image, while re-encoding and storing the display image.
This type of prior art data-transceiving equipment is now described in detail with reference to the drawings.
FIG. 5 is a block diagram illustrating the prior art data-transceiving equipment.
The data-transceiving equipment as illustrated in FIG. 5 includes a received data-separating unit 106, a decoding unit 104, a graphics-generating unit 105, an image-blending unit 103, an image-displaying unit 100, an encoding unit 101, a storing unit 102, and a control unit 107.
The received data-separating unit 106 separates received data, in which encoded image data is multiplexed with graphics data, into these two pieces of encoded image data and graphics image data.
The received data-separating unit 106 feeds the separated, encoded image data and the separated graphics data into the decoding unit 104 and the graphics-generating unit 105, respectively.
The decoding unit 104 decodes the encoded image data from the received data-separating unit 106. The decoding unit 104 feeds the decoded image data into the image-blending unit 103.
The graphics-generating unit 105 generates graphics image data based on the graphics data from the received data-separating unit 106. The graphics image data include texts, two-dimensional images, or three-dimensional images. The graphics-generating unit 105 feeds the generated graphics image data into the image-blending unit 103.
The image-blending unit 103 blends the image data from the decoding-unit 104 with the graphics image data from the graphics-generating unit 105, thereby producing display image data. The image-blending unit 103 feeds the display image data into the image-displaying unit 100.
The image-displaying unit 100 displays an image based on the display image data from the image-blending unit 103.
Upon receipt of instructions from the control unit 107 to record the displayed image, the image-displaying unit 100 transmits the display image data to the encoding unit 101.
The encoding unit 101 encodes the display image data from the image-displaying unit 100. The encoding unit 101 feeds the encoded display image data into the storing unit 102.
The storing unit 102 stores the encoded display image data from the encoding unit 101.
As described above, the prior art data-transceiving equipment is adapted to decode and then blends several pieces of received, encoded image data with each other to provide a display image, thereby displaying the display image, while re-encoding and storing the display image.
The decoding unit 104 retrieves the stored display image data from the storing unit 102 in response to instructions from the control unit 107 to replay the display image. The decoding unit 104 decodes the retrieved display image data.
The decoded display image data is fed into the image-displaying unit 100 through the image-blending unit 103. The image-displaying unit 100 displays an image based on the decoded display image data.
In recent years, the use of the data-transceiving equipment as described above has resulted in an increasing number of data-transceiving equipment with a moving image-communicating function such as a videophone function. More specifically, such functional data-transceiving equipment is designed to display a blended image on the image-displaying unit 100 as well as displaying, on the image-displaying unit 100, only an image obtained by decoding the received encoded image data. The blended image includes a received image, an image taken into the data-transceiving equipment through a camera on the data-transceiving equipment, and a generated graphics image from the graphics-generating unit 105.
For example, assume that a first user having one videophone-equipped handset communicates with a second user having another videophone-equipped handset. In the first user's videophone-equipped handset, a main image formed by a decoded image of primarily the second user from, the second user's videophone-equipped handset is blended with several sub-images that include a first user's self-portrait and a graphics image. The first user's self-portrait is entered into the first user's videophone-equipped handset through a built-in camera on the first user's videophone-equipped handset. The graphics image is generated in the first user's videophone-equipped handset. As a result, such a blended image is displayed as a display image on the image-displaying unit 100.
The blended display image is not always used as such because of possible reuse thereof. More specifically, the blended display image may be once recorded. Then later the recorded display image may be replayed, edited, and transmitted.
For example, when the first user and the second user communicate with one another using the videophone-equipped handsets, the first user may want to watch only a second user's image, first and second user's images, or only a graphics image. Further variations in image may be considered.
As a result, when the data-transceiving equipment including the prior art data-transceiving equipment stores and encodes ultimate display images, there objectionably occurs image loss caused by an overlap of blended images. In addition, some necessary part of the blended images must disadvantageously be taken out therefrom.
A problem with the prior art data-transceiving equipment is, that it is difficult to meet such requirements, with a concomitant decrease in user-friendliness.